Allocator-aware @safe reference counting is still not possible

[Dukc]

On Monday, 30 January 2023 at 17:36:59 UTC, Paul Backus wrote:
> As far as I am aware, it is impossible to have all three of the 
> following:
>
> 1. @safe containers.
> 2. User-supplied allocators.
> 3. No language changes.

Earlier I presented the idea to require a `@trusted` 
"certificate" function from the allocator. You agreed that it 
satisfies all of these in principle, but you wouldn't consider it 
in practice because it'd be embarrassing to explain for an 
outsider.

Can you elaborate why? Maybe we can have some further ideas.